Fig. 2From: Association between SMAD3 gene polymorphisms and osteoarthritis risk: a systematic review and meta-analysisMeta-analysis for the association between SMAD3 rs12901499 polymorphism and OA risk. The squares and horizontal lines denote the ORs and 95% CIs of individual studies, and the size of the squares corresponds to the study-specific weight. The hollow diamond denotes the pooled OR and 95% CIBack to article page